Help wanted for assembly constraint

[Anonymous]

The  6mm peg should follow the 6mm helical slot to impart axial movement to the inner cylinder....I cannot  select the right constraint?

This should be similar to nut and bolt!.

Windows 7    Inventor 2014

[Anonymous]

The  6mm peg should follow the 6mm helical slot to impart axial movement to the inner cylinder....I cannot  select the right constraint?

This should be similar to nut and bolt!.

Windows 7    Inventor 2014

[JDMather · Accepted solution]

There are several different solutions (I will try to post examples as time permits).

The first solution involves Contact Sets (drag slowly - if you go to fast the computer can't keep up).

(I noticed that your sketches were not constrained - so I modeled the parts from scratch.)

[JDMather · Accepted solution]

There are several different solutions (I will try to post examples as time permits).

The first solution involves Contact Sets (drag slowly - if you go to fast the computer can't keep up).

(I noticed that your sketches were not constrained - so I modeled the parts from scratch.)

[johnsonshiue]

Hi! There are a few ways to handle this type of case. I personally prefer using Transitional constraint. Please take a look at attached file. The main problem here is that the actual intersection between the pin and the slot should only be a straight line. Any face-based constraint could have problems handling the situation.

Instead of using the solid faces, I created a small sphere at the bottom of the pin and also I created zero-offset surface on top of the slot. By doing so, the motion becomes fairly simple: just a sphere moving on a face.

There is some design issue on the slot. The intersection between the extrusion cut and the coil cut is not smooth. It could be a problem in real world. I added a fillet to smooth it out.

Please take a look and let me know if you have any question.

Thanks!

[johnsonshiue]

Hi! There are a few ways to handle this type of case. I personally prefer using Transitional constraint. Please take a look at attached file. The main problem here is that the actual intersection between the pin and the slot should only be a straight line. Any face-based constraint could have problems handling the situation.

Instead of using the solid faces, I created a small sphere at the bottom of the pin and also I created zero-offset surface on top of the slot. By doing so, the motion becomes fairly simple: just a sphere moving on a face.

There is some design issue on the slot. The intersection between the extrusion cut and the coil cut is not smooth. It could be a problem in real world. I added a fillet to smooth it out.

Please take a look and let me know if you have any question.

Thanks!

[Anonymous]

Thank you...the sphere was used and works.

[Anonymous]

Thank you...the sphere was used and works.